Investigating the recency effect in intonation drift

Abstract

Intonation drift is a gradual drift out of tune by as much as a semitone that often occurs in unaccompanied choirs. This thesis explores intonation drift from the perspective of two serial position effect mechanisms: the recency interval mechanism and the primacy interval mechanism. The contribution of these two mechanisms to intonation drift is investigated over three experiments. In Experiment 1, it was assumed that intonation judgements of musical intervals in short-term memory would be made via comparison with reference intervals stored in long-term memory. As such, Experiment 1 determined the threshold value for when an interval was perceived to be out of tune. Experiment 2 investigated what might affect pitch error when reproducing a single pitch. Experiment 3 detuned melodies by various amounts as guided by the threshold value found in Experiment 1, in order to investigate if different detune amounts resulted in pitch error differences when reproducing the first note of a melody. Results indicated that the recency interval mechanism contributed to pitch error in addition to the primacy interval mechanism. Additionally, pitch errors in reproducing the first note of a melody appeared to plateau once the detuning was perceivable, and pitch errors were the largest when detuning was not perceivable. The latter finding may explain why pitch drift can be as much as a semitone in intonation drift. This research has implications for choir rehearsal strategies and vocal pedagogy.

Date of Award	2018
Original language	English